pwm: Add support for R-Car PWM Timer
This patch adds support for R-Car SoCs PWM Timer. The PWM timer of R-Car H2 has 7 channels. So, we can use the channels if we describe device tree nodes. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Yoshihiro Shimoda
Thierry Reding
parent
7260d25145
commit
ed6c1476bf
3 changed files with 286 additions and 0 deletions
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@ -277,6 +277,17 @@ config PWM_PXA
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To compile this driver as a module, choose M here: the module
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will be called pwm-pxa.
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config PWM_RCAR
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tristate "Renesas R-Car PWM support"
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depends on ARCH_RCAR_GEN1 || ARCH_RCAR_GEN2 || COMPILE_TEST
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depends on HAS_IOMEM
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help
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This driver exposes the PWM Timer controller found in Renesas
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R-Car chips through the PWM API.
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To compile this driver as a module, choose M here: the module
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will be called pwm-rcar.
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config PWM_RENESAS_TPU
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tristate "Renesas TPU PWM support"
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depends on ARCH_SHMOBILE || COMPILE_TEST
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@ -25,6 +25,7 @@ obj-$(CONFIG_PWM_MXS) += pwm-mxs.o
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obj-$(CONFIG_PWM_PCA9685) += pwm-pca9685.o
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obj-$(CONFIG_PWM_PUV3) += pwm-puv3.o
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obj-$(CONFIG_PWM_PXA) += pwm-pxa.o
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obj-$(CONFIG_PWM_RCAR) += pwm-rcar.o
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obj-$(CONFIG_PWM_RENESAS_TPU) += pwm-renesas-tpu.o
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obj-$(CONFIG_PWM_ROCKCHIP) += pwm-rockchip.o
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obj-$(CONFIG_PWM_SAMSUNG) += pwm-samsung.o
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274
drivers/pwm/pwm-rcar.c
Normal file
274
drivers/pwm/pwm-rcar.c
Normal file
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@ -0,0 +1,274 @@
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/*
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* R-Car PWM Timer driver
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*
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* Copyright (C) 2015 Renesas Electronics Corporation
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*
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* This is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*/
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include <linux/pwm.h>
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#include <linux/slab.h>
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#define RCAR_PWM_MAX_DIVISION 24
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#define RCAR_PWM_MAX_CYCLE 1023
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#define RCAR_PWMCR 0x00
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#define RCAR_PWMCR_CC0_MASK 0x000f0000
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#define RCAR_PWMCR_CC0_SHIFT 16
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#define RCAR_PWMCR_CCMD BIT(15)
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#define RCAR_PWMCR_SYNC BIT(11)
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#define RCAR_PWMCR_SS0 BIT(4)
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#define RCAR_PWMCR_EN0 BIT(0)
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#define RCAR_PWMCNT 0x04
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#define RCAR_PWMCNT_CYC0_MASK 0x03ff0000
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#define RCAR_PWMCNT_CYC0_SHIFT 16
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#define RCAR_PWMCNT_PH0_MASK 0x000003ff
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#define RCAR_PWMCNT_PH0_SHIFT 0
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struct rcar_pwm_chip {
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struct pwm_chip chip;
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void __iomem *base;
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struct clk *clk;
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};
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static inline struct rcar_pwm_chip *to_rcar_pwm_chip(struct pwm_chip *chip)
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{
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return container_of(chip, struct rcar_pwm_chip, chip);
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}
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static void rcar_pwm_write(struct rcar_pwm_chip *rp, u32 data,
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unsigned int offset)
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{
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writel(data, rp->base + offset);
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}
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static u32 rcar_pwm_read(struct rcar_pwm_chip *rp, unsigned int offset)
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{
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return readl(rp->base + offset);
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}
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static void rcar_pwm_update(struct rcar_pwm_chip *rp, u32 mask, u32 data,
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unsigned int offset)
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{
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u32 value;
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value = rcar_pwm_read(rp, offset);
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value &= ~mask;
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value |= data & mask;
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rcar_pwm_write(rp, value, offset);
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}
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static int rcar_pwm_get_clock_division(struct rcar_pwm_chip *rp, int period_ns)
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{
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unsigned long clk_rate = clk_get_rate(rp->clk);
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unsigned long long max; /* max cycle / nanoseconds */
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unsigned int div;
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if (clk_rate == 0)
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return -EINVAL;
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for (div = 0; div <= RCAR_PWM_MAX_DIVISION; div++) {
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max = (unsigned long long)NSEC_PER_SEC * RCAR_PWM_MAX_CYCLE *
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(1 << div);
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do_div(max, clk_rate);
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if (period_ns < max)
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break;
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}
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return (div <= RCAR_PWM_MAX_DIVISION) ? div : -ERANGE;
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}
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static void rcar_pwm_set_clock_control(struct rcar_pwm_chip *rp,
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unsigned int div)
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{
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u32 value;
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value = rcar_pwm_read(rp, RCAR_PWMCR);
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value &= ~(RCAR_PWMCR_CCMD | RCAR_PWMCR_CC0_MASK);
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if (div & 1)
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value |= RCAR_PWMCR_CCMD;
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div >>= 1;
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value |= div << RCAR_PWMCR_CC0_SHIFT;
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rcar_pwm_write(rp, value, RCAR_PWMCR);
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}
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static int rcar_pwm_set_counter(struct rcar_pwm_chip *rp, int div, int duty_ns,
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int period_ns)
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{
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unsigned long long one_cycle, tmp; /* 0.01 nanoseconds */
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unsigned long clk_rate = clk_get_rate(rp->clk);
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u32 cyc, ph;
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one_cycle = (unsigned long long)NSEC_PER_SEC * 100ULL * (1 << div);
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do_div(one_cycle, clk_rate);
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tmp = period_ns * 100ULL;
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do_div(tmp, one_cycle);
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cyc = (tmp << RCAR_PWMCNT_CYC0_SHIFT) & RCAR_PWMCNT_CYC0_MASK;
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tmp = duty_ns * 100ULL;
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do_div(tmp, one_cycle);
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ph = tmp & RCAR_PWMCNT_PH0_MASK;
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/* Avoid prohibited setting */
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if (cyc == 0 || ph == 0)
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return -EINVAL;
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rcar_pwm_write(rp, cyc | ph, RCAR_PWMCNT);
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return 0;
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}
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static int rcar_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip);
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return clk_prepare_enable(rp->clk);
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}
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static void rcar_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip);
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clk_disable_unprepare(rp->clk);
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}
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static int rcar_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
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int duty_ns, int period_ns)
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{
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struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip);
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int div, ret;
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div = rcar_pwm_get_clock_division(rp, period_ns);
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if (div < 0)
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return div;
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/* Let the core driver set pwm->period if disabled and duty_ns == 0 */
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if (!test_bit(PWMF_ENABLED, &pwm->flags) && !duty_ns)
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return 0;
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rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR);
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ret = rcar_pwm_set_counter(rp, div, duty_ns, period_ns);
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if (!ret)
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rcar_pwm_set_clock_control(rp, div);
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/* The SYNC should be set to 0 even if rcar_pwm_set_counter failed */
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rcar_pwm_update(rp, RCAR_PWMCR_SYNC, 0, RCAR_PWMCR);
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return ret;
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}
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static int rcar_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip);
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u32 value;
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/* Don't enable the PWM device if CYC0 or PH0 is 0 */
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value = rcar_pwm_read(rp, RCAR_PWMCNT);
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if ((value & RCAR_PWMCNT_CYC0_MASK) == 0 ||
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(value & RCAR_PWMCNT_PH0_MASK) == 0)
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return -EINVAL;
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rcar_pwm_update(rp, RCAR_PWMCR_EN0, RCAR_PWMCR_EN0, RCAR_PWMCR);
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return 0;
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}
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static void rcar_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
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{
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struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip);
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rcar_pwm_update(rp, RCAR_PWMCR_EN0, 0, RCAR_PWMCR);
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}
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static const struct pwm_ops rcar_pwm_ops = {
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.request = rcar_pwm_request,
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.free = rcar_pwm_free,
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.config = rcar_pwm_config,
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.enable = rcar_pwm_enable,
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.disable = rcar_pwm_disable,
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.owner = THIS_MODULE,
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};
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static int rcar_pwm_probe(struct platform_device *pdev)
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{
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struct rcar_pwm_chip *rcar_pwm;
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struct resource *res;
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int ret;
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rcar_pwm = devm_kzalloc(&pdev->dev, sizeof(*rcar_pwm), GFP_KERNEL);
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if (rcar_pwm == NULL)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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rcar_pwm->base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(rcar_pwm->base))
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return PTR_ERR(rcar_pwm->base);
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rcar_pwm->clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(rcar_pwm->clk)) {
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dev_err(&pdev->dev, "cannot get clock\n");
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return PTR_ERR(rcar_pwm->clk);
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}
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platform_set_drvdata(pdev, rcar_pwm);
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rcar_pwm->chip.dev = &pdev->dev;
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rcar_pwm->chip.ops = &rcar_pwm_ops;
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rcar_pwm->chip.base = -1;
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rcar_pwm->chip.npwm = 1;
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ret = pwmchip_add(&rcar_pwm->chip);
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if (ret < 0) {
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dev_err(&pdev->dev, "failed to register PWM chip: %d\n", ret);
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return ret;
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}
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pm_runtime_enable(&pdev->dev);
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return 0;
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}
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static int rcar_pwm_remove(struct platform_device *pdev)
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{
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struct rcar_pwm_chip *rcar_pwm = platform_get_drvdata(pdev);
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pm_runtime_disable(&pdev->dev);
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return pwmchip_remove(&rcar_pwm->chip);
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}
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static const struct of_device_id rcar_pwm_of_table[] = {
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{ .compatible = "renesas,pwm-rcar", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, rcar_pwm_of_table);
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static struct platform_driver rcar_pwm_driver = {
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.probe = rcar_pwm_probe,
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.remove = rcar_pwm_remove,
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.driver = {
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.name = "pwm-rcar",
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.of_match_table = of_match_ptr(rcar_pwm_of_table),
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}
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};
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module_platform_driver(rcar_pwm_driver);
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MODULE_AUTHOR("Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>");
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MODULE_DESCRIPTION("Renesas PWM Timer Driver");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:pwm-rcar");
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